Saldana, who also appeared in 2010 comic book-based feature "The Losers," was still in full Gamora green-skinned make-up and decorative facial prosthetics when she sat down last fall on the film's London set for a roundtable discussion with reporters including CBR News, to discuss heading to the stars again, this time with Marvel and writer/director James Gunn.

Zoe Saldana: To me, it's no more of a concern than Cate Blanchett or Keira Knightley need to have because they've done a few period pieces. Just because I've done a film that's considered, among the masses that like to characterize things, as science fiction, so be it. As an artist, I like working with filmmakers that have the balls to imagine the unimaginable. Those are the radicals that I identify with. I grew up in a household where there were a lot of stories set in unconventional places and I found the escape rewarding. And, on the basis of being a woman, by playing an alien I also get to avoid playing someone's girlfriend here on Earth.

In the make-up department we saw the various treatments for Gamora's look. Did they try different versions on you?

We had maybe seven or eight camera tests, and the idea with mine was, "How alien do we want her to look?" From my perspective, I felt that she had to be pretty, which is something I don't normally think about with other characters I play, but because I was going to be green and the lead girl I wanted to make sure boys found me attractive. Everyone else was like, "Contacts? Dyed hair? Wig or no wig? What color? How long?" And I was like "Pretty! Get the teenage boy vote!"

You've done other properties that appeal to that demographic so it's interesting that it came up on this one.

It's because I'm older. You wonder if you're losing your sex appeal, you know, when you're green for four months. But then you start to find your character appealing and beautiful in how different she looks.

Chris [Pratt] said he wasn't told to look at the comics. Did you look at any?

No. I didn't look at anything for "Star Trek," either. As actors, you have this trait to imitate very easily, but I don't want to limit myself in finding this creature, this woman. If I read the comics I'd be cheating myself out of the adventure that I find so beautiful, which is conceiving a character. That part belongs to me, and it's what I remember the most about what I do.

How does putting make-up on change the way you act and move?

It's funny, when it came to Gamora my approach was very different from when I played Neytiri [in "Avatar"]. There, the dehumanization of myself was absolutely crucial, because these creatures came with very specific requirements as defined by James [Cameron]. In this one, because it's a dark comedy -- we're like the Rolling Stones of the Marvel Cinematic Universe, we're the ones who always failed in class and now get to burn the house down -- there was a contemporary sense that I didn't want to tamper with. I didn't focus too much on making Gamora distinctly alien, because then you're going to lose a lot of other things. This movie runs really fast and for the demographic it's aimed at, if I get too intricate, they're going to be like, "Huh, she's kinda weird." So part of doing this and aging -- now I'm 35 -- is that you take all those things into consideration when you're bringing a character together.

Gamora has a detailed past and lots of interesting personality traits. What was the most appealing thing to you in when you were signing on to play her?

My nephew's 11, and he's the only person I know who actually reads "Guardians," and I would talk to him and he asked me who I thought Gamora was. So I said, "Oh, she's a warrior." And he said "But not only is she a warrior, but she's an assassin, and she's very lethal, but what saves her is what can also doom her, and that's that she's very righteous." And that was coming from an 11 year old!

That's the overall mojo of Gamora, her sense of wanting to do the right thing. Which is why she tries to convince the others not to sell their souls for money. She's the one that starts going in that direction first. That's what I like about this movie. We're all starting as lost kids, and by running away from our families we end up creating our own and becoming decent people.

You've done some good weapon-wielding in previous films, what's different and fun about the weapons and action in this one?

This time around it was a sword. It's very heavy and my wrists are very thin, so I have this insecurity that I look wimpy! It's so much better to have a gun. I'm more prepared, I've trained with Seals, it's fine. But the moment I've got a knife I'm like, "Oh god! Take it, it's too heavy!"

You rely on really good stunt people. I'm working with a woman called Chloe [Bruce] and she's the stealth Gamora, and we're building a character together. It's important when working on a movie to work with the stuntperson, not just by memorizing the choreography but also studying that individual and having them study you, so that you're not playing two different people. And in order for the actor's wishes to be respected in terms of the characteristics that your character has, you have to have good and talented stuntpeople that don't just carry weapons well, but can also carry a personality.

For Gamora, it'd be easy for me not to invest in the action part of it and not aid the stunt team, but it's like... instead of looking like Jackie Chan, we think why don't we make her look like Jet Li? That allows her to maintain some kind of grace. I was very adamant that the choreographers should study the bullfighters and the way they seduce a bull into surrendering to his own death just with a rag. It's a very sensual dance and eventually the bull caves in and accepts his own death, which I thought would be a pretty interesting trait for Gamora to have -- using her charms to get her way in a fight.

Can you talk about Gamora's relationship with the other characters? What's it like in the movie?

She finds Quill interesting, but he's such a douche at first, very immature. I think she's intrigued by Groot. At least, I am! He's so human, despite looking the most inhuman, and he has a sense of compassion. In terms of getting her to soften herself, Groot is definitely a subject to study. And then she thinks Drax is such a drama queen! But she learns that she's not the only victim. Drax has lost his family too, and probably in front of him like Gamora. Rocket had a lot of alterations done to him, and so did Gamora. And Quill lost his mom and was taken from his home. So there are a lot of things they all have in common.

With Nebula, it's complicated. That's the biggest heartbreak for Gamora; that she couldn't save her sister. They have very similar paths, but Gamora wants to change. She's just different. Nebula was probably born wanting to taste blood, and that's something very frustrating for Gamora because there's a big responsibility that she feels, and Nebula doesn't see it that way. It's very heartbreaking.

Who's your favorite character?

I think Nebula's costume's really hot. The transformation is wonderful. The balls on [Karen Gillan], to shave her head! I'd have been like "Dude, how much are you paying me? No, I can't." So, her. And I'm fascinated by Dave [Bautista]'s Drax make-up. There's that thing in the Comic-Con trailer where he's like yelling in slow motion -- then when you meet him in real life, he's so tender, so sensitive. Very soft spoken and kind, but a kick-ass actor. So's Chris as well, the transformation is not just physical, he's really devoted himself to this character.

It's wonderful to come to work and be surrounded by people taking their job so seriously, because the day you feel like slacking you immediately correct yourself. To come to set and see happy people in-character after 8 hours in make-up, it makes you know you have to bring your game.

Gamora's direct connection to Thanos makes her the anchor to the greater Marvel Cinematic Universe that's been established. Is that something that was part of your process?

If I tell you "no," will you think ill of me? I don't follow comics, so I've only learned of the importance Thanos has with all these characters while doing the movie, and I thought she does have an upper hand because she was raised by this individual. But in terms of how deep those blood ties run? That'll probably be covered in the next movie!